The fisher is a small, carnivorous mammal native to North America, and is sometimes misleadingly referred to as a fisher cat, although it is not a cat. These forest-dwelling creatures have been trapped since the 18th century for their fur. Their pelts were in such demand that they were extirpated from several parts of the United States in the early part of the 20th century. Fisher are carnivores, consuming snowshoe hare, porcupine, small rodents, upland birds, and carrion of deer, moose, and beaver. Fisher will also eat foods that are seasonally available, such as fruits and nuts. Contrary to their name, fisher do not typically eat fish.

Fisher habitat use is governed by the availability of food, topography, cover, den locations, and weather. Fisher use a wide variety of forest habitats. They avoid open areas (roads, fields, open bogs, and large clear-cuts) with no overhead cover, however edges surrounding these areas are extensively used. Logs, brush piles, trees, and ground burrows are utilized for cover and protection while resting. Fishers are more likely to be found in old-growth forests. Since female fishers require moderately large trees for denning, forests that have been heavily logged and have extensive second growth appear to be unsuitable for their needs.